Ive been looking on various forums and this is pretty much what ive gathered
3570k has PCIe 3.0 support and runs about 5% faster than 2500k at stock speeds but tends to run alittle bit hotter than the SB chips
2500k is a cheap efficient chip that overclocks very well and doesn't particularly have any heat issues.
To give alittle detail. I plan on getting the ASrock extreme4 z77 MOBO regardless of whatever CPU i choose. I AM USING THIS PURELY FOR GAMING, I also will be running with my current Hyper 212+ with Arctic formula 5 for cooling, and i plan to upgrade to 2 gtx 680's in SLI and lastly i plan to overclock to 4.0 Ghz and perhaps more in the later future (few months maybe)
Keeping in mind that i have a mid range CPU cooler and the 3570k runs hot and the fact that i will eventually have 2 gtx 680's in my rig.
Is the 3570k worth the effort with its PCIe 3.0 support but poor OC temps or does the PCIe 3.0 support not really help at all with frame rates?